The present invention relates to a method and apparatus for dispersing and transporting particulate matter.
U.S. Pat. No. 3,859,205 issued to Reba et. al. describes a system utilizing the Coanda effect to separate or disperse particulate matter such as polyethylene fibers or the like and transport the dispersed fibers to a predetermined location. The system of U.S. Pat. No. 3,859,205 has been utilized in conjunction with a forming bell to lay down a layer of fibers that have been dispersed and transported on to a moving wire to form a nonwoven web. While the system of U.S. Pat. No. 3,859,205 has been satisfactory in most respects some operational difficulties have arisen under certain conditions.
In particular, in the arrangement of U.S. Pat. No. 3,859,205 particulate matter such as polyethylene fibers is supplied to the first nozzle assembly thereof through a supply pipe at right angles to the main axis of the first nozzle assembly. Thus, the fibers must turn substantially 90 degrees prior to entering the first flow path defined by the first nozzle assembly. Because of centrifugal forces, fibers tend to be separated from the air stream with which they are associated and move to the outside when making the turn. Thus, the apparatus is not loaded symmetrically at the outset, resulting in nonuniformity of the web being formed by the system. Still other problems of nonuniformity have been created by a swirling effect that occasionally takes place within the first nozzle assembly as a result of the fibers making the aforesaid 90 degree turn.
It is therefore an object of the present invention to provide an improved apparatus and method for dispersing and transporting particulate matter resulting in the more uniform distribution of particulate matter such as polyethylene fibers.